基坑支护及降水

1、Project Description工程概述

费列罗食品(杭州)有限公司项目位于杭州经济技术开发区江东新区高技术产业区域内，新建总建筑面积约46615㎡，其中地下建筑面积约535㎡，主要为生产车间贯穿东西的地下通道：基底埋深为3.6m（相对±0.000为-4.7）。

The FERRERO FOOD (HANGZHOU) CO.,LTD Project is located in Hangzhou Economic & Technical development area (HEDA), the area for this new construction is 46615m2, among them there are 535m2 basement works, which is went through the production shop from East to West, it’s about 3.6m underground (which is -4.7m referring to ±0.000 level)

2、地质概况Geological condition

2.1地形地貌：本场地地貌属冲海积平原地貌单元，场地地形平坦，大部分为耕地，地面高程多在4.8-5.2米左右，局部分布有条带状积水沟，沟深约在0.5-1米左右。场地南北两侧分别有江东一路、江东二路通过，西侧有新建的青西四路通过。

The ground surface status: this area is a part of an Alluvial and coast plain, the surface is flat, most are cultivated land, the floor level is between 4.8 and 5.2m, there is also local strip shaped water pound, the depth is various from 0.5 to 1m. there is JiangdongYilu at south side and JiangdongErlu at North side, the QIngxiSilu is at west side.

2.2岩土层的构成及特征：根据本阶段勘探孔揭露的地层情况，场区上部为新近堆积的耕土、冲海相沉积的粉、砂土层，中部为海相沉积的粉土层及陆相沉积的粘土层、砂砾石层。

The character of soil and rock layer: according to geological borehole investigation, the upper part is cultivated soil and sedimentation of clay/sand layer, the middle par is sediment of silt soil layer and continental sedimentation for clay layer and gravel layer.

2.3地下水：场区地处钱塘江南岸，属钱塘江流域，拟建场地周边水系比较发育：根据地下水赋存条件、水力特征及岩土的水理性质，场地勘探深度范围内地下水主要为第四系松散岩类孔隙水，第四系松散岩类孔隙水又可分为孔隙潜水和孔隙承压水。

Underground water: the construction field is located at the south bank of Qiantangjiang, it is part of qiangtangjiang watershed, the water system is well developed at the surrounding: refer to the underground water accumulation condition/ the water pressure condition and Geotechnical water character, the underground water at this investigation area is water accumulated in the loose rock joints, and it includes water with and without pressure.

3、初步设计支护及降水形式：双轴水泥搅拌桩+挂网喷浆的基坑支护和轻型井点降水系统组成。

The support and lower-down water solution: cement mixed piling + shotcrete with mesh for foundation pit, and small sized well pit water lower-down system.

4、施工方法construction method

4.1 双轴水泥搅拌桩double axis cement mixed piling

⑪施工工艺（见下表）construction process (see below diagram)

⑫施工技术措施construction technical measurements

① 挖沟槽：沟槽开挖深度1.5～2m，宽度大于设计搅拌桩挡土墙宽度0.5m。

Ditch excavation: the depth for ditch excavation is 1.5m~2m, the width should be 0.5m wider than the designed pile wall width.

②布设桩位:按设计要求使用经纬仪测放各围护桩轴线及桩中心位置，各桩点采用固定标志确定桩中心位置，桩位布置的偏差不得大于20mm。

Arrangement of the pile location: according to the design, the pile location shall be setout with theodolite for its axis, the location shall